Automatic control of devices in production lines, plants, and the like is generally performed using a control device such as a programmable logic controller (PLC) and a human machine interface (HMI). In recent years, a large-scale control system including a plurality of control devices coupled to one another via a network has also been developed. Such a control system can have a configuration in which two or more control devices are accommodated in one network, or a configuration in which two or more networks are connected to one another.
In a control system including a plurality of control devices, label names may be sometimes used. A label name is a character string associated with a control device. Each label name is assigned with a freely-selected character string, e.g. a character string that means the name of the control device. A label name may also be used as a variable in a program. In order to improve program readability, a character string indicating the content of a variable is often used as a label name.
The control devices communicate with one another to exchange information necessary for their control. Such communication is performed based on memory accesses for reading information from a memory equipped in a control device and writing information in a memory. In order to perform a memory access, an access source control device needs to store path information indicating a path to an access destination control device. Conventionally, such path information has been manually generated by a user, and the generated path information has been manually written in each control device. Manual generation of path information is inefficient and error-prone.
Patent Literature 1 discloses a device that automatically creates path information indicating a path between control devices. In response to an identifier (ID) of a control device being designated, the device disclosed in Patent Literature 1 generates network routing information that is path information for the designated control device, based on network configuration information. Thus, it is possible to efficiently generate the path information and prevent erroneous path information from being generated.